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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sat, 6 Jan 2018 17:27:59 -0800
Message-ID: <CA+55aFwV45NpYdjGZQ_FCvvdvxWYDEwV_Qosvyxi4UbhupWOrQ@mail.gmail.com>
Subject: Re: [PATCH v5 05/12] x86/retpoline/ftrace: Convert ftrace assembler
 indirect jumps
To: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>,
        Andi Kleen <ak@linux.intel.com>, Paul Turner <pjt@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linux-foundation.org>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Kees Cook <keescook@google.com>,
        Rik van Riel <riel@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Jiri Kosina <jikos@kernel.org>,
        One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
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Sender: linux-kernel-owner@vger.kernel.org

On Sat, Jan 6, 2018 at 11:53 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Sat, 6 Jan 2018, Linus Torvalds wrote:
>
>>
>> [ Goes off and looks ]
>>
>> Oh. The AMD lfence version wants a register. Oh well.
>
> The register load could be put into the macro itself, though we need to
> supply a scratch register

Yeah, not worth it I suspect. I guess we can live with the register version.

             Linus